The present invention relates to fuels as energy sources for oil-burning devices such as diesel engines, jet engines, turbines, and heating furnaces such as used in the home, and, more particularly, to synthetic or substitute fuels which can replace or be used in combination with known fuel sources. Fossil fuel sources are becoming more expensive as the supply slowly decreases. It is recognized that, in the future, such supplies may become depleted.
In the past, attempts have been made to use alkyl fatty esters as additives to gasoline. U.S. Pat. No. 1,692,784, issued Nov. 20, 1928, teaches the use of small amounts of alkyl fatty esters as a detergent additive for gasoline to remove carbon formed as the result of burning the low octane natural gasolines being used in automobile engines at that time, i.e., 1928. Since alkyl fatty esters would not vaporize in the carburetors of ordinary automobile gasoline engines when used as a fuel itself, the use was limited to small amounts as an additive only.
Furthermore, oil-burning engines, such as the automobile diesel engine, were not introduced for commercial use until about the year 1936. Accordingly, U.S. Pat. No. 1,692,784 is limited in its teaching of using alkyl fatty esters as an additive for gasoline in gasoline engines. Even if alkyl fatty esters could have been utilized as a fuel in accordance with the teachings of the patent, undesirable results would be obtained such as lowering the octane number of the gasoline, decreasing the mechanical efficiency of gasoline engines, increasing engine knock and causing build-up of carbon in the engines. The latter result is the very problem which was taught to be avoided when the alkyl fatty esters were used only as an additive to gasoline.
Efforts have been made to preserve the present supply of gasoline by reducing its use and even mixing other fuels such as alcohol therewith. However, such efforts have been primarily directed to fuels such as gasoline for use in automobile gasoline engines.
In the past, petroleum middle distillates such as diesel oil were popular because of greater burning efficiency and lower price. However, the cost of these fuels has also increased significantly and is approaching the price of gasoline. Accordingly, there is a need for a fuel which will preserve or extend the supply of petroleum middle distillates to meet the increasing demand for these fuel-efficient products.